Solve for $a$, $ \dfrac{a - 4}{2a - 9} = \dfrac{1}{7} $
Solution: Multiply both sides of the equation by $2a - 9$ $ a - 4 = \dfrac{2a - 9}{7} $ Multiply both sides of the equation by $7$ $ 7(a - 4) = 2a - 9 $ $7a - 28 = 2a - 9$ $5a - 28 = -9$ $5a = 19$ $a = \dfrac{19}{5}$